• Authors:
    • Cadisch, G.
    • Giller, K.
    • Kamiri, H.
    • Gathumbi, S.
    • Ndufa, J.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 6
  • Year: 2009
  • Summary: The deliberate planting of fast-growing N 2-fixing legume monoculture species in rotation with cereal crops can be an important source of N for soil fertility replenishment. We hypothesized that mixed-species fallows have a higher potential of giving long-term residual benefits in terms of biomass, nutrients, and quality of residuals leading to long-term nutrient supply to postfallow maize ( Zea mays L.) crops. To test these hypotheses, two experiments were established in farmers' fields on very fine Kandiudalfic Eutrudox soils with monoculture and mixed-species fallows. Treatments included: sesbania [ Sesbania sesban (L.) Merr.], crotalaria ( Crotalaria grahamiana Wight and Arn.), pigeonpea [ Cajanus cajan (L.) Millsp.], siratro [ Macroptilium atropurpureum (DC.) Urb.], and calliandra ( Calliandra calothyrsus Meissn.) as monoculture-species fallow and mixture fallows of sesbania+crotalaria, sesbania+pigeonpea, sesbania+siratro, or sesbania+calliandra compared with continuous maize cropping with or without N fertilizer, and natural weed fallow. Total aboveground biomass ranged from 4.1 to 20.5 Mg ha -1 for monoculture and 7.8 to 23.3 Mg ha -1 for mixed-species fallows. Recyclable fallow biomass N ranged from 70 to 313 kg ha -1 and there was a positive interaction in some mixtures leading to increased N accumulation. Postfallow maize yields for fallows over five cropping seasons were 161-272% or 61-103% higher when compared with continuous maize without or with N fertilizer, respectively. Long-term postfallow effects on maize yield were linearly related to the amount of recycled fallow N yield. Thus, choice of fallow species to mix should be primarily driven by a better risk management strategy and an increased basket of multiple products and services.
  • Authors:
    • Sudhakar, S.
    • Ashish, P.
    • Panda, S.
    • Pandey, V.
  • Source: Environmental Geology
  • Volume: 56
  • Issue: 5
  • Year: 2009
  • Summary: An effort was made to identify the critical sub-watersheds for the development of best management plan for a small watershed of Eastern India using a hydrological model, namely, AVSWAT2000. A total of 180 combinations of various management treatments including crops (rice, maize, groundnut and soyabean), tillage (zero, conservation, field cultivator, mouldboard plough and conventional practices) and fertilizer levels (existing half of recommended and recommended) have been evaluated. The investigation revealed that rice cannot be replaced by other crops such as groundnut, maize, mung bean, sorghum and soyabean since comparatively these crops resulted in higher sediment yield. The tillage practices with disc plough have been found to have more impact on sediment yield and nutrient losses than conventional tillage practices for the existing level of fertilizer. Sediment yield decreased in the case of zero tillage, conservation tillage, field cultivator, mouldboard plough, and conservation tillage as compare to conventional tillage. Lowest NO 3-N loss was observed in zero tillage in all the fertilizer treatments, whereas field cultivator, mouldboard plough and disc plough resulted in increase of NO 3-N loss. As compared to conventional tillage, the losses of soluble phosphorus were increased in mouldboard plough. The losses of organic nitrogen were also increased as fertilizer dose increased. After zero tillage the conservation tillage performed better in all the fertilizer treatments as per loss of organic nitrogen and organic phosphorus is concerned. It can be concluded that the sediment yield was found to be the highest in the case of disc plough followed by mouldboard plough, field cultivator, conventional tillage, field cultivator and least in zero tillage practices. The nutrient losses were found to be in different order with tillage practices, resulted highest in disc plough tillage practices. In view of sediment yield and nutrient losses, the conservation tillage practice was found to be the best as the sediment yield is less than the average soil loss whereas nutrient loss is within the permissible limit.
  • Authors:
    • Balasubramanian, V.
    • Kumar, A.
    • Prabhu, M.
    • Jagadeesan, R.
  • Source: Asian Journal of Horticulture
  • Volume: 4
  • Issue: 1
  • Year: 2009
  • Summary: This review discusses the various cropping systems (multiple cropping, intercropping and cover cropping) that are successfully adopted for some tropical vegetables in India, including a few tuber vegetables. The role of cropping systems in crop protection (specifically the management of diamond back moth [ Plutella xylostella] in cabbage using collard as a trap crop, use of maize as an intercrop to control a viral disease of pepper, reduction of the incidence of bacterial wilt caused by Pseudomonas solanacearum [ Ralstonia solanacearum] in tomato by intercropping, and use of French marigold [ Tagetes patula] as a trap crop for the control of Meloidogyne incognita on potato) is briefly discussed.
  • Authors:
    • Mozny, M.
    • Zalud, Z.
    • Dubrovsky, M.
    • Semeradova, D.
    • Trnka, M.
    • Hlavinka, P.
  • Source: Agricultural and Forest Meteorology
  • Volume: 149
  • Issue: 3-4
  • Year: 2009
  • Summary: The relationship between seasonal agricultural drought and detrended yields (within a period from 1961 to 2000) of selected crops was assessed in the conditions of the Czech Republic, which are to some extent representative of a wider area of Central Europe. Impact of water stress was analyzed using time series of yields for 8 crops (spring barley, winter wheat, grain maize, potato, winter rape, oats, winter rye and hay from permanent meadows) for 77 districts in the Czech Republic (average district area is 1025 km(2)). Relative version of Palmer's Z-index (rZ-index or rZ-i) was used as a tool for quantification of agricultural drought. The monthly values of the rZ-index for each individual district were calculated as the spatial average (only for the grids of arable land). The study showed that severe droughts (e.g., in 1981 and 2000) are linked with significant reduction in yields of the main cereals and majority of other crops through the most drought prone regions. We found a statistically significant correlation (p
  • Authors:
    • Hoogmoed, W. B.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: This proceedings contains 9 papers providing information on the potential of conservation tillage in a wide-range of geographical, climatological and socioeconomical situations. Results from studies in China, Australia, Iran and Ethiopia are presented. Topics covered include: sustainable tillage methods for irrigated wheat production in different regions of Iran; conservation tillage models for small-scale farming; functional relationships between soil water infiltration and wheeling and rainfall energy; controlled traffic farming in restoring soil structure; short-term effects of tillage and manure on some soil physical properties and maize root growth in a sandy loam soil in western Iran; the impact of 14 years of conventional and no-till cultivation on the physical properties and crop yields of a loam soil at Grafton NSW, Australia; conservation tillage implements and systems for smallholder farmers in semi-arid Ethiopia; controlled traffic farming with no tillage for improved fallow water storage and crop yield on the Chinese Loess Plateau; the effect of alternative tillage and residue cover on yield and water use efficiency in annual double cropping system in North China Plain.
  • Authors:
    • Celep, H.
    • Tosun, S.
    • Tiryaki, I.
    • Idikut, L.
  • Source: African Journal of Biotechnology
  • Volume: 8
  • Issue: 19
  • Year: 2009
  • Summary: A 2-year field study was conducted to evaluate effects of nitrogen (0, 12.5, 25 kg/da N) rates and previous crops on 2 hybrid corn cv Maverik and Bora varieties planted as second crop following either chickpea or wheat during 2004 and 2005. Split-split plot experimental design was used with 4 replications. Tasseling period, ear silk period, first ear height, plant height, stem diameter, ear length, 1000 seed weight, seed weight of each ear and seed yield parameters were evaluated. Results indicated that effects of previous crops for ear silk period, 1000 seed weight, seed weight of each ear and seed yield of corn varieties were highly significant during both years, while first ear height and ear length were significantly different during 2004, only. The N rates significantly affected tasseling period, ear silk period, first ear height, plant height and seed yield during both years. Effect of N rates was also significant for stem diameter and ear length during 2004 while 1000 seed weight was significant during 2005, only. There were significant differences between 2 corn varieties for tasseling period, ear silk period, first ear height, ear length, seed weight of each ear during both years whereas 1000 seed weight and seed yield showed significant differences during 2004 and stem diameter showed a significant difference during 2005, only. There was a previous crop x N rate interaction for seed yield during both years while significant previous crop x N rate interactions were determined for 1000 seed weight and seed weight of each ear in 2005. This study suggested that N rates and corn cultivars might result significant differences on tasseling period, ear silk period, first ear height, ear length and seed weight of each ear. The results also indicated that species of previous crops significantly affect corn seed yield and yield parameters and winter legumes such as chickpea might help to maximize corn yield in a crop rotation system.
  • Authors:
    • Barbercheck, M. E.
    • Jabbour, R.
  • Source: Biological Control
  • Volume: 51
  • Issue: 3
  • Year: 2009
  • Summary: The growing demand for organic products creates opportunities for farmers. Information on the consequences of management practices can help farmers transition to organic and take advantage of these prospects. We examined the interaction between soil disturbance and initial cover crop on naturally occurring entomopathogenic fungi (EPF) during the 3-year transition to organic production in a feed grain rotation in central Pennsylvania. Our experiment included four systems comprised of a factorial combination of two levels of primary tillage (full vs. reduced) and two types of initial cover crop (timothy/clover vs. rye/vetch). The cropping sequence consisted of an initial cover crop, followed by soybean, and finally, maize. The entire experiment was replicated in time, with the initiation lagged by 1 year. We detected four species of EPF (Metarhizium anisopliae, Beauveria bassiana, Isaria fumosorosea, and Isaria farinosa) by bioassay of soil samples collected four times during each field season. The latter three species were detected infrequently; therefore, we focused statistical analysis on M. anisopliae. Detection of M. anisopliae varied across sampling date, year in crop sequence, and experimental start, with no consistent trend across the 3-year transition period. M. anisopliae was isolated more frequently in the systems initiated with timothy/clover cover crops and utilizing full tillage; however, we only observed a tillage effect in one temporal replicate. M. anisopliae detection was negatively associated with soil moisture, organic matter, and zinc, sulfur, and copper concentrations in the soil. This study helps to inform farmers about management effects on soil function, specifically conservation biological control. (C) 2009 Elsevier Inc. All rights reserved.
  • Authors:
    • Karayel, D.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: The purpose of this research was to examine the performance of a modified precision vacuum seeder for no-till sowing of maize ( Zea mays L.) and soybean ( Glycine max L.) following wheat ( Triticum aestivum). A wavy-edged disc and side gauge wheels were fabricated and mounted to each unit of a common precision vacuum seeder (with a hoe opener on one row unit and a double disc-type opener on another row unit) and used to sow at three forward speeds (1.0, 1.5 and 2.0 m s -1). Multiple index, miss index, quality of feed index and precision of the distribution of the seeds along the length of the row, sowing depth uniformity, mean emergence time and percent emergence were determined. Sowing depth uniformity, mean emergence time and percent emergence of both maize and soybean seeds were decreased and precision of the distribution of the seeds along the length of the row was increased as a result of increasing forward speed. The distribution of the seeds along the length of the row, sowing depth uniformity and percent emergence of the seeder equipped with the double disc-type opener was better than the seeder equipped with the hoe-type opener. The precision of the distribution of the seeds along the length of the row for forward speeds of 1.0 and 1.5 m s -1 experienced in this study was well below 29%, and therefore is acceptable for both maize and soybean seeds. The modified precision vacuum seeder generally performed best using the double disc-type furrow opener at the forward speed of 1.0 m s -1, based on the distribution of the seeds along the length of the row, sowing depth uniformity, and percent emergence.
  • Authors:
    • Mastrorilli, M.
    • Katerji, N.
  • Source: European Journal of Agronomy
  • Volume: 30
  • Issue: 2
  • Year: 2009
  • Summary: The effect of soil texture on water use efficiency (WUE) was analyzed for six crops cultivated on loam and clay soils. Results were obtained after a long-term study, carried out in a lysimetric set-up, in conditions of experimental neutrality (climate, agro-techniques, and variety were the same for each crop) with the sole exception of the soil texture, which was the variable to be studied. In the case of potato, corn, sunflower, and sugar beet, WUE was reduced significantly when crops were grown in clay soil. The reductions ranged from 22% to 25%. The decrease of WUE in clay soil was coupled with significant reductions in yield and in ET, except in the case of the corn crop. The reduction in WUE in corn depended solely on the yield decrease. A 10% decrease in WUE values was also observed for the soy-bean and tomato grown in clay soil, but it was not statistically significant. Different causes which may reduce the WUE values observed in the clay soil are discussed. It seems coherent to hypothesize that, during the active growing phase, a deficit in water uptake occurs in the plants growing in the clay soil. This hypothesis is consistent with the observations of stomatal conductance, daily evapotranspiration, and leaf surface. In conclusion, the operative development of this study is outlined.
  • Authors:
    • Aiken, R. M.
    • Currie, R. S.
    • Klocke, N. L.
  • Source: Transactions of the ASABE
  • Volume: 52
  • Issue: 1
  • Year: 2009
  • Summary: Crop residues have value when left in the field and also when removed from the field and sold as a commodity. Reducing soil water evaporation (E) is one of the benefits of leaving crop residues in place. E was measured beneath a maize canopy at the soil surface with nearly full coverage by maize stover or standing wheat stubble. E was also measured from a soil surface that was partially covered with corn stover without crop shading. E was measured with mini-lysimeters that were 300 mm in diameter and 140 mm deep. Surface coverage and amount of dry matter of crop residues influenced E. E was reduced nearly 50% compared with bare soil E when maize stover and wheat stubble nearly covered the surface under a maize canopy during the growing season. Partial surface coverage, from 25 to 75%, with corn stover caused small reductions in E compared with bare soil when there was no crop canopy. Full surface coverage reduced energy limited E 50 to 65% compared with E from bare soil with no shading. No-till management, using crop residues to significantly reduce E, required soil surfaces to be nearly covered. Economic benefits of crop residues for E suppression during the growing season can be as much as $365 ha -1.